[PATCH] Revert "printk: wake up all waiters"

From: John Ogness
Date: Thu May 26 2022 - 16:31:05 EST


This reverts commit 938ba4084abcf6fdd21d9078513c52f8fb9b00d0.

The wait queue @log_wait never has exclusive waiters, so there
is no need to use wake_up_interruptible_all(). Using
wake_up_interruptible() was the correct function to wake all
waiters.

Since there are no exclusive waiters, erroneously changing
wake_up_interruptible() to wake_up_interruptible_all() did not
result in any behavior change. However, using
wake_up_interruptible_all() on a wait queue without exclusive
waiters is fundamentally wrong.

Go back to using wake_up_interruptible() to wake all waiters.

Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
---
kernel/printk/printk.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a3e1035929b0..ea3dd55709e7 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3904,7 +3904,7 @@ static void wake_up_klogd_work_func(struct irq_work *irq_work)
}

if (pending & PRINTK_PENDING_WAKEUP)
- wake_up_interruptible_all(&log_wait);
+ wake_up_interruptible(&log_wait);
}

static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) =
--
2.30.2